Manual for Usb to RS232 driver works with Modem on Linux RedHat 8.0
For other version RedHat system, please reference flowing step.
Copying pl2303.c to the /usr/src/linux2.4/drivers/usb/serial.
Change directory to /usr/src/linux2.4
copy /usr/scr/linux2.4/configs/kernel-2.4.18-i686.config to /usr/src/linux2.4 as .config
Type “make menuconfig” on /usr/src/linux2.4 directory.
Choose “Loadable module Support --” to uncheck “Set version information……” item and then leave this sub menu. (Appendix A.)
Choose “General setup --” to selects “[*] Kernel .config support” and leave this sub menu.
Choose “USB support --” “USB Serial Converter support --” to uncheck all the driver module expect “USB Generic Serial Driver” and “USB Prolific 2303 Single …….” and then leave this sub menu.
Finally to leave this menuconfig and save it.
To modify the extension name of Makefile as you want to show up on GRUB menu.
Type “make clean; make dep; make bzImage; make modules; make modules_install; make install” and click “Entry”.
Wait for kernel compiled, and the reboot the system, and then to choose kernel name that you modified on GRUB menu to boot you own system up.
After system ready, type “uname -all” to check the kernel name is your defined (for example: linux-2.4.18-14philip), if it is original Linux kernel name, you have some thing wrong during building kernel, please go back to the step 3 to try again.
If it is successfully, go /lib/modules/2.4.18-14philip/kernel/drivers/usb/serial to check pl2303.o has exist this folder, if it is not, please go back to step 10 to try again.
Plug in PL-2303X to the USB port, and type “dmesg” on consol, the last message will identify the PL-2303X attached on ttyUSB0.
Type minicom -s xxxxxx to create a script file for PL-2303X modem.
When you first time to runs minicom, it will stay on consol mode, they “CTRL-A and then Z” to pop menu up, and then choose “O” to configure modem.
On “configuration” menu, choose “Serial port setup” to set A—Serial Device: as /dev/ttyUSB0, and then set E - Bps/Par/Bits: as 57600 8N1 and then leave.
On the same menu, choose “Save setup as xxxxxx” and then choose “exit” to initialization modem and minicom.
If your setup is correctly, now the state would be modem ready.
Type “CTRL-A and then D” to open dial up setting menu to fill in necessary information for dial, and then try to dial up modem to connect to ISP.
If it is successfully, now the PL-2303X is ready for use.
Close minicom to return X windows.
Choose StartSystem Toolsinternet Configuration Wizard to select “Device Type” as Modem connection and click Forward, fill in dialup information on next dialog box, and the click Apply.
Selects Hardware page on next dialog box to set Modem Device: /dev/ttyUSB0, Baud Rate: 115200, Flow Control: Hardware (CRTSCTS), and then click OK.
Go back to Devices page to choose a Profile, and then click Activate button to dial up to ISP.
If it is successfully, now you can join to internet by the browser.
Appendix A. about how to building a custom kernel, please refer the www.redhat.com/docs/manuals/linux